Valve stem vacuum seal



April 21V, 1953 G. E. HANSEN VALVE STEM VACUUM SEAL Filed June l0, 1950 Patented Apr. 21, 1953 UNITED STATI VALVE STEM VACUUM SEAL George E. Hansen, Chicago, Ill., assignor to Crane Co., Chicago, Ill., a corporation of Illinois Application June 10, 1950, Serial No. 167,295

Z Claims.

This invention pertains to a shaft vacuum seal, and, more specifically, it pertains to a vacuum seal located around a valve stem or the like whereby iiuid entering the said valve is intercepted by the said vacuum seal and carried away.

An object of this invention is to provide a vacuum seal to be employed in connection with a vacuum valve or the like, to thereby prevent fluid inltration into the vacuum line.

Other objects and advantages will become more readily apparent upon reading the following description in light of the accompanying drawings, in which:

Fig. 1 is a fragmentary sectional assembly view of an upper portion of a valve showing a preferred embodiment of this invention.

Fig. 2 is an enlarged sectional view taken on a line 2--2 of Fig. 1.

Similar reference numerals refer to similar parts in the several views.

In Fig. 1, the upper portion of a valve is shown employing a preferred embodiment of this invention. For the purpose of a description of this invention, it is not deemed necessary to show the lower portion of the said valve as that is of a conventional structure. The particular vacuum seal of this invention is suitable for any structure wherein a stem or rod is inserted into a vacuum line, and it is desired to prevent any possible fluid inltration into the said vacuum line.

Thus, in Fig. 1 is shown a conventional stem III which, in addition to being rotatable, may, of course, be of the rising or non-rising type. Conneeted to the top of the stem IIJ, to actuate the same, is the usual handwheel Il secured thereto by means of a nut I2, threaded into the stem Ill. The usual bonnet I3 is shown mounted around the stem I to enclose a portion of the same. The bottom of the bonnet I3 is threaded into the valve body (not shown) to be fiuidtight therewith in the usual manner. An upper inner portion I4 of the bonnet I3 is relieved to receive Ya stuing box bushing or an adapter I5 which is bored as illustrated to mount relatively snugly over the stem I0. The upper face I6 of the adapter I5 is depressed or formed to support what is termed a chevron packing I'I over which an adapter or washer i8 is located. A gland I8, mounted yaround the stem ID, abuts the top face of the second adapter member or washer I8, and a threaded packing nut 20 abuts a shoulder 2l of the gland I9, threadedly engaging the bonnet I3 to eiect this assembly of the upper portion of the valve.

With more particularity in describing this invention, a fluid seal means consisting of an 0- ring 24 is disposed between the stem I0 and the upper portion of the gland I9, and another O- ring 25 is located between the lower portion of the gland I9 and the bonnet I3 in the respective grooves, as illustrated. The top face of the adapter I8 is preferably provided with four equally spaced radially extending transverse grooves 2l, as shown in Fig. 2. The lower portion of the gland I9 contains a counterbore 22 to provide a chamber 26 between the stem I0 and the gland I9. A tube 23 extends through the gland I9 to communicate with the chamber 2E, while the opposite end of the tube 23 is connected to a vacuum pump (not shown).

It should here be understood that only two possible passageways exist for any fluid to enter the upper portion of the valve. Fluid passing O-ring 24 will enter the chamber 26 and be exhausted therefrom through the vacuum tube 23, while Huid passing the O-ring 25 will pass through the adapter grooves 21 and into the chamber 25 and then exhaust through the tube 23.

Thus, there has been provided a positive means of preventing any iiuid from entering the upper portion of a valve operating in a vacuum line, effectively preventing undesirable infiltration.

Although this invention has been described in but one speciiic form, it should not be so limited as it is susceptible to changes and should be limited only by the spirit thereof and the scope of the appended claims.

I claim:

l. A valve stem vacuum seal comprising a Valve stem, a bonnet member surrounding a portion of the said stem and suitably connecting with the valve body, a packing material in iiuidtight relation with a portion of the said stem, a plurality o adapters, one of said adapters being positioned above the said packing and having a plurality of radi-ally extending grooves across the top surface thereof, a gland having a projecting portion and forming said annular chamber with said stem and abutting the said adapter grooved face,

the said chamber communicating with the Said grooves, a vacuum tubular member extending .into the projecting portion of the said gland communicating with the said chamber, inner and outer means on the said gland for sealing the said chamber and adapter in substantial fluidtightness with the exterior of the valve.

2. A valve stem vacuum seal comprising a valve stem, a packing gland mounted around a portion of the said valve stem to provide a chamber therebetween, a packing material in fluidtight relation with at least a portion of the said stem, upper and lower adapters mounted around the said stern above and below said packing mate rial and with the upper one of the adapters having a plurality of radial grooves therein to register with the said chamber, Vacuum means cooperating with the said gland communicating with the said chamber, pressure actuated sealing means on inner and outer peripheral portions of the said packing gland for maintaining the said 4 chamber and the said adapter respectively in substantial uidtight condition with relation to fluid pressure external to the said valve.

GEORGE E. HANSEN.

References Cited in the le of this patent UNTED STATES PATENTS Number Name Date 313,180 Colwell Mar. 3, 1885 1,582,786 Rhodes Apr. 27, 1926 2,369,249 Rainalter Feb. 13, 1945 

